/// <summary>
/// 添加字段
/// </summary>
/// <param name="context"></param>
/// <param name="model"></param>
/// <param name="property"></param>
public static void AddField(this DynamicModelDbContext context, RuntimeModelMeta model, RuntimeModelMeta.ModelPropertyMeta property)
{
using (DbConnection conn = context.Database.GetDbConnection())
{
if (conn.State != System.Data.ConnectionState.Open)
{
conn.Open();
}
DbCommand addFieldCmd = conn.CreateCommand();
addFieldCmd.CommandText = $"alert table {model.ClassName} add {property.PropertyName} ";
switch (property.ValueType)
{
case "int":
addFieldCmd.CommandText += "int";
break;
case "datetime":
addFieldCmd.CommandText += "datetime";
break;
case "bool":
addFieldCmd.CommandText += "bit";
break;
default:
addFieldCmd.CommandText += "nvarchar(max)";
break;
}
addFieldCmd.ExecuteNonQuery();
}
}
/// <summary>
/// 反序列化获得集合
/// </summary>
/// <param name="meta"></param>
/// <returns></returns>
public static RuntimeModelMeta.ModelPropertyMeta[] GetProperties(this RuntimeModelMeta meta)
{
if (string.IsNullOrEmpty(meta.Properties))
{
return(null);
}
return(JsonConvert.DeserializeObject <RuntimeModelMeta.ModelPropertyMeta[]>(meta.Properties));
}
/// <summary>
/// 创建模型表(sql server)
/// </summary>
/// <param name="context"></param>
/// <param name="model"></param>
public static void CreateModel(this DynamicModelDbContext context, RuntimeModelMeta model)
{
DbConnection conn = context.Database.GetDbConnection();
if (conn.State != System.Data.ConnectionState.Open)
{
conn.Open();
}
DbCommand createTableCmd = conn.CreateCommand();
createTableCmd.CommandText = $"create table {model.ClassName}";
createTableCmd.CommandText += "(id int identity(1,1)";
foreach (var p in model.GetProperties())
{
createTableCmd.CommandText += $",{p.PropertyName} ";
switch (p.ValueType)
{
case "int":
createTableCmd.CommandText += "int";
break;
case "datetime":
createTableCmd.CommandText += "datetime";
break;
case "bool":
createTableCmd.CommandText += "bit";
break;
case "timestamp":
createTableCmd.CommandText += "timestamp";
break;
case "string":
if (p.Length != 0)
{
createTableCmd.CommandText += "nvarchar(" + p.Length + ")";
}
else
{
createTableCmd.CommandText += "nvarchar(max)";
}
break;
default:
createTableCmd.CommandText += "nvarchar(max)";
break;
}
}
createTableCmd.CommandText += ")";
createTableCmd.ExecuteNonQuery();
}
/// <summary>
/// 删除字段
/// </summary>
/// <param name="context"></param>
/// <param name="model"></param>
/// <param name="property"></param>
public static void RemoveField(this DynamicModelDbContext context, RuntimeModelMeta model, string property)
{
using (DbConnection conn = context.Database.GetDbConnection())
{
if (conn.State != System.Data.ConnectionState.Open)
{
conn.Open();
}
DbCommand removeFieldCmd = conn.CreateCommand();
removeFieldCmd.CommandText = $"alert table {model.ClassName} DROP COLUMN {property}";
removeFieldCmd.ExecuteNonQuery();
}
}
//创建模型表
public static void CreateModel(this ModelDbContext context, RuntimeModelMeta model)
{
using (DbConnection conn = context.Database.GetDbConnection())
{
if (conn.State != System.Data.ConnectionState.Open)
{
conn.Open();
}
DbCommand createTableCmd = conn.CreateCommand();
createTableCmd.CommandText = $"create table {model.ClassName}";
createTableCmd.CommandText += "{id int identity(1,1)";
foreach (var p in model.Properties)
{
createTableCmd.CommandText += $",{p.PropertyName} ";
switch (p.ValueType)
{
case "int":
createTableCmd.CommandText += "int";
break;
case "datetime":
createTableCmd.CommandText += "datetime";
break;
case "bool":
createTableCmd.CommandText += "bit";
break;
default:
createTableCmd.CommandText += "nvarchar(max)";
break;
}
}
createTableCmd.CommandText += "}";
createTableCmd.ExecuteNonQuery();
}
}
public IActionResult Index()
{
List <RuntimeModelMeta.ModelPropertyMeta> modelmeta = new List <RuntimeModelMeta.ModelPropertyMeta>();
modelmeta.Add(new RuntimeModelMeta.ModelPropertyMeta()
{
Id = 1,
PropertyName = "Size",
Name = "尺寸",
ValueType = "string",
Length = 20
});
modelmeta.Add(new RuntimeModelMeta.ModelPropertyMeta()
{
Id = 2,
PropertyName = "Name",
Name = "名称",
ValueType = "string",
Length = 20
});
modelmeta.Add(new RuntimeModelMeta.ModelPropertyMeta()
{
Id = 3,
PropertyName = "Color",
Name = "颜色",
ValueType = "string",
Length = 20
});
modelmeta.Add(new RuntimeModelMeta.ModelPropertyMeta()
{
Id = 4,
PropertyName = "Version",
Name = "版本",
ValueType = "timestamp"
});
var s = JsonConvert.SerializeObject(modelmeta);
RuntimeModelMeta meta = new RuntimeModelMeta();
meta.ClassName = "BareDiamond";
meta.ModelName = "BareDiamond";
meta.Properties = s;
_modeldbContext.Add(meta);
_modeldbContext.SaveChanges();
foreach (var item in _modeldbContext.Metas)
{
_dbContext.CreateModel(item);
}
Type modelType = _privader.GetType(1); //获取id=1的模型类型
object obj = Activator.CreateInstance(modelType); //创建实体
var entity = obj as DynamicEntity; //类型转换，目的是进行赋值
entity["Id"] = 1;
entity["Name"] = "名称";
entity["Size"] = "10*20";
entity["Color"] = "red";
_dbContext.Add(entity);
_dbContext.SaveChanges();
return(View());
}
//这个方法就是把一个RuntimeModelMeta转换成更接近类结构的TypeMeta对象
private TypeMeta GetTypeMetaFromModelMeta(RuntimeModelMeta meta)
{
TypeMeta typeMeta = new TypeMeta();
//我们让所有的动态类型都继承自DynamicEntity类，这个类主要是为了方便属性数据的读取，具体代码看后面
typeMeta.BaseType = typeof(DynamicEntity);
typeMeta.TypeName = meta.ClassName;
foreach (var item in meta.GetProperties())
{
TypeMeta.TypePropertyMeta pmeta = new TypeMeta.TypePropertyMeta();
pmeta.PropertyName = item.PropertyName;
//如果必须输入数据，我们在属性上增加RequireAttribute特性，这样方便我们进行数据验证
if (item.IsRequired)
{
TypeMeta.AttributeMeta am = new TypeMeta.AttributeMeta();
am.AttributeType = typeof(RequiredAttribute);
am.Properties = new string[] { "ErrorMessage" };
am.PropertyValues = new object[] { "请输入" + item.Name };
pmeta.AttributeMetas.Add(am);
}
if (item.ValueType == "string")
{
pmeta.PropertyType = typeof(string);
TypeMeta.AttributeMeta am = new TypeMeta.AttributeMeta();
//增加长度验证特性
am.AttributeType = typeof(StringLengthAttribute);
am.ConstructorArgTypes = new Type[] { typeof(int) };
am.ConstructorArgValues = new object[] { item.Length };
am.Properties = new string[] { "ErrorMessage" };
am.PropertyValues = new object[] { item.Name + "长度不能超过" + item.Length.ToString() + "个字符" };
pmeta.AttributeMetas.Add(am);
}
else if (item.ValueType == "int")
{
if (!item.IsRequired)
{
pmeta.PropertyType = typeof(int?);
}
else
{
pmeta.PropertyType = typeof(int);
}
}
else if (item.ValueType == "datetime")
{
if (!item.IsRequired)
{
pmeta.PropertyType = typeof(DateTime?);
}
else
{
pmeta.PropertyType = typeof(DateTime);
}
}
else if (item.ValueType == "bool")
{
if (!item.IsRequired)
{
pmeta.PropertyType = typeof(bool?);
}
else
{
pmeta.PropertyType = typeof(bool);
}
}
else if (item.ValueType == "timestamp")
{
pmeta.PropertyType = typeof(byte[]);
}
typeMeta.PropertyMetas.Add(pmeta);
}
return(typeMeta);
}
/// <summary>
/// 把集合序列化成字符串，用于保存
/// </summary>
/// <param name="meta"></param>
/// <param name="properties"></param>
public static void SetProperties(this RuntimeModelMeta meta, RuntimeModelMeta.ModelPropertyMeta[] properties)
{
meta.Properties = JsonConvert.SerializeObject(properties);
}
